The transdermal route of parenteral delivery of drugs provides many advantages and transdermal systems for delivering a wide variety of drugs or other beneficial agents are described in U.S. Pat. Nos. 3,598,122, 3,598,123, 4,379,454, 4,286,592 and 4,314,557, for example, all of which are incorporated herein by reference. In many cases, drugs which would appear to be ideal candidates for transdermal delivery are found to have such low permeability through intact skin that they cannot be delivered at therapeutically effective rates from reasonably sized systems. In an effort to increase skin permeability it has been proposed to pretreat the skin with various chemicals or to concurrently deliver the drug in the presence of a permeation enhancers. Various materials have been suggested for this purpose as described in U.S. Pat. Nos. 4,299,826, 4,343,798, 4,046,886, 4,130,643, 4,405,616, 4,335,115, 4,130,667, 3,903,256, 4,379,454, 3,527,864, 3,952,099, 3,896,238, 3,472,931 which are incorporated herein by reference, British Pat. No. 1,001,949 and Idson, Percutaneous Absorption, J. Phar. Sci., Vol. 64, No. b 6, June 1975, pp. 901-924 (particularly 919-921). To be considered useful a permeation enhancer should possess certain characteristics in addition to its ability enhance the permeability of at least one and preferably a large number of drugs. These characteristics include being non-toxic, non-irritating on prolonged exposure and under occlusion, and non-sensitizing on repeated exposure. Preferably it shuld also be odorless and capable of delivering drugs without producing burning or tingling sensations.
According to our invention, we have discovered that polyethylene glycol monolaurate (PEGML), an emollient composition presently listed in the Cosmetic Ingredient Directory, is highly effective in enhancing the permeation of a large number of drugs and other therapeutic or beneficial agents through body surfaces and membranes, generally, and skin, particularly, and when formulated in pharmaceutical compositions with other materials appears to satisfy the criteria noted above.
It is accordingly an object of our invention to increase the permeability of body surfaces of animals and humans, including the mucosa and other membranes and more particularly of human skin, to the transport of drugs and other beneficial agents by the concurrent application of the drug or beneficial agent and PEGML to the body surface.
It is another object of our invention to provide compositions of matter for application to the skin which comprise PEGML and a transdermally deliverable drug or beneficial agent.
It is another object of our invention to provide transdermal therapeutic systems for the concurrent delivery of PEGML and a drug or beneficial agent.